Background Traumatic injuries are of global health concern and significant contributors to Emergency Department (ED) and hospital workload.

Aim To compare patterns of traumatic injuries among patient presentations to the ED across different modes of arrival (ambulance, police, or private transport) and to examine the predictors of an ED length of stay (LOS) exceeding 4 hours and hospital admission requirement.

Methods A retrospective observational study using 6 months of health data (8th October 2012–7th April 2013) of ED patient presentations made to one large, regional ED in Queensland, Australia, with a diagnosis code related to trauma.

Findings Over 6 months, 24.2% (n = 6,668) of adult patient presentations were trauma-related; most (60.9%) arrived via privately arranged transport (PAT); 38.7% were brought in by ambulance (BIBA) and 0.4% were brought in by police (BIBP). Demographics, clinical profile and patient outcomes differed based on mode of arrival. One in four patient presentations required hospital admission and 25% had an ED length of stay of >4 hours. Factors influencing hospital admission included older age, night shift, more emergent priority, and being BIBA. An ED length of stay of >4 hours was associated with older age, being BIBA, emergent nature of presentation, and hospital admission.

Conclusion The profile and outcomes of ED patient presentations with traumatic injury differs based on their mode of arrival to the ED. People BIBA were more likely to require hospital admission and have longer ED LOS, compared with those BIBP or PAT, even when controlling for covariates. Our findings may be used to inform nursing resource allocation when considering mode of arrival, especially for older people and people BIBA.